This relates generally to electronic devices and, more particularly, to electronic devices with displays.
Electronic devices often include displays. For example, an electronic device may have a liquid crystal display in which liquid crystal display pixels are used to display images for a user. Liquid crystal displays often include light-emitting diode backlight units for providing backlight illumination. Display efficiency can be adversely affected by inefficiencies in producing backlight illumination and in transmitting backlight illumination through liquid crystal display structures. Liquid crystal display structures also exhibit limited contrast ratios. Organic light-emitting diode displays have been developed that exhibit high contrast ratios, but these devices may consume more power than desired due to the inefficiencies in their organic light-emitting diodes. It can also be challenging to ensure that organic light-emitting diodes exhibit desired lifetimes.
To address some of the shortcomings of liquid crystal displays and organic light-emitting diode displays, displays have been developed that are based on arrays of discrete inorganic light-emitting diodes. In this type of display, driver circuits may be implemented using silicon integrated circuits that are dispersed among the array of light-emitting diodes. Each integrated circuit may control light output from an associated set of nearby light-emitting diodes. Although this type of arrangement may be satisfactory for certain displays, it may be difficult to achieve design goals for some displays such as displays with low power requirements. For example, leakage current limitations may make it difficult or impossible to use this type of circuitry to drive displays that are operating at low refresh rates to conserve power.
It would therefore be desirable to be able to provide improved circuitry for controlling the operation of electronic device displays such as displays based on arrays of light-emitting diodes.